This invention relates to mechanical assemblies which enable vehicles of greater than one track to lean, generally towards the center point of a turning radius. Within the set of prior art the following subsets are known:
Those which employ electromechanical systems to gauge turn or lean and proportionally actuate devices to act upon the vehicle frame or wheels, such as U.S. Pat. No. 5,765,846. These suffer from complexity derived from the necessary use of control algorithms, signal processing, or both.
A subset of the established art includes hydraulically actuated leaning devices, such as U.S. Pat. No. 4,546,997. The use of heavy hydraulic fluid systems and associated hardware in complex closed loop systems significantly increases the overall weight of leaning vehicles as well as necessitates the use of sensor systems in order to measure vehicle frame lean and act upon the hydraulic system in order to act or counteract the vehicle roll.
In another subset of the prior art mechanical linkages are used to allow for vehicle frame lean in relationship to the wheels and road surface, such as U.S. Pat. No. 4,087,106. These make no provision for the restoration to a neutral vehicle attitude upon the completion of turning or handling maneuvers. Further, the designs which rely on the rider or driver to restore the vehicle to a neutral position cannot be used in embodiments which are relatively large or heavy compared to the rider.
The herein described embodiments overcome various combinations of the significant limitations of the prior art.